Temperature Control for Research and Industry. Model 280 Timer Manual

Transcription

1 Temperature Control for Research and Industry Model 280 Timer Manual

2 Warranty J-KEM Scientific, Inc. warrants this unit to be free of defects in materials and workmanship and to give satisfactory service for a period of 12 months from date of purchase. If the unit should malfunction, it must be returned to the factory for evaluation. If the unit is found to be defective upon examination by J-KEM, it will be repaired or replaced at no charge. However, this WARRANTY is VOID if the unit shows evidence of having been tampered with or shows evidence of being damaged as a result of excessive current, heat, moisture, vibration, corrosive materials, or misuse. This WARRANTY is VOID if devices other than those specified in Section 3.11 are powered by the controller. Components which wear or are damaged by misuse are not warranted. This includes contact points, fuses and solid state relays. THERE ARE NO WARRANTIES EXCEPT AS STATED HEREIN. THERE ARE NO OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND OF FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL J-KEM SCIENTIFIC, INC. BE LIABLE FOR CONSEQUENTIAL, INCIDENTAL OR SPECIAL DAMAGES. THE BUYER'S SOLE REMEDY FOR ANY BREACH OF THIS AGREEMENT BY J-KEM SCIENTIFIC, INC. OR ANY BREACH OF ANY WARRANTY BY J-KEM SCIENTIFIC, INC. SHALL NOT EXCEED THE PURCHASE PRICE PAID BY THE PURCHASER TO J-KEM SCIENTIFIC, INC. FOR THE UNIT OR UNITS OF EQUIPMENT DIRECTLY AFFECTED BY SUCH BREACH. Service J-KEM Scientific maintains its own service facility and technical staff to service all parts of the controller, usually in 24 hours. For service, contact: J-KEM Scientific, Inc Olive Blvd. (314) FAX (314) jkem911@jkem.com Internet Catalog: This manual contains parameters specific to temperature controller Serial #. When calling with a technical question, please have the controller s serial number available. You ve purchased the most versatile controller available to the research community. We re confident it can regulate ANY heating/cooling situation you ll ever encounter. If the information in this User s Manual isn t adequate to make your application work, call our engineering department for assistance. With J-KEM s patented Microtune circuitry 2

3 INDEX SECTION PAGE 1. QUICK OPERATING INSTRUCTIONS KEM-NET DATA LOGGING AND CONTROL SOFTWARE ADJUSTING THE CONTROLLER FOR STABLE CONTROL WITH DIFFERENT HEATERS What is Tuning Autotuning Procedure Tuning for Heating Mantles: A Special Case Sensor Placement OPERATIONS GUIDE Front Panel Description Setting the Controller for Safe Operation Ramp-to-Setpoint & Soak Feature Temperature Sensor Input Timer Controls Power Reduction Circuit Affect of Power Setting on Heating Profile Do's and Don't's When Using Your Controller Changing the Temperature Display Resolution Resetting the Controller for Use With Heating Mantles Heater Restrictions Fusing Changing between PID and ON/OFF Operating Modes Troubleshooting APPLICATION NOTES Theory of How the Controller Works Simply Controlling the Heating Mantle Temperature Directly Automatic Storage of Min/Max Temperatures How to Set Up a Reaction With Your Temperature Controller APPENDIX I. Using the Controller With an Oil Bath (Application Note 1) II. Safety Considerations and Accurate Temperature Control III. Resetting the Controller to Original Factory Settings WARNING: Adhere to the restrictions of SECTION Failure to do so may create a significant safety hazard and will void the warranty. 3

4 Section 1: Quick Operating Instructions The five steps below are the basics of using your temperature controller. The User s Manual is a reference that explains the controller more fully as well as some of its more sophisticated features. It s recommended that new users unfamiliar with process controllers read the entire manual carefully. The controller is preprogrammed for use with heating mantles fitted to round bottomed flasks running typical organic reactions (i.e., nonpolymeric reactions in solvents such as THF, toluene, DMF, etc.). For a primer on how to set up a reaction with your temperature controller: See Section 4.4 To use heaters other than heating mantles: See Section 2. Do not use the controller to heat oil baths: See Section 3.2 & Appendix I. For polymer synthesis, atypical, expensive, or safety critical reactions: See Appendix II. The Model 280 contains two completely independent temperatuer controllers in a single cabinet. Each independent channel consits of a primary setpoint meter (the temperature control meter), an over-temperature meter, and a digital timer. The instructions below apply to both controller channels individually. 1 Enter an Over Temperature Limit. This meter is the back-up meter for the main temperature controller. Set this meter about 5 o C higher than that entered in the main controller in Step 5. If the reaction reaches this temperature for any reason, heating is automatically discontinued until manually reset. See Section 3.2. Press the RED Reset Button. This resets the over temperature circuit and prepares the controller for use. The probe temperature must be below the temperature of the limit controller on the left for this circuit to reset. 2 Place the thermocouple in the solution being heated. Place at least the first 1/4 of the thermocouple directly in the solution being heated. Thermocouples can be bent without harming them. If you re heating a corrosive liquid, use Teflon coated thermocouples. If you are heating a sealed reaction, see Section Set the power level switch to the volume of solution being heated not the size of the flask being used). The power level switch can be thought of as a solid state variac. Volume ranges are printed above this switch as a guide to select the correct power level since it s easier to guess the volume being heated than the appropriate percent power to apply to a heater. Heat Off turns off the heater so the controller displays temperature only. All new users should read Section 3.6. A power setting of... is equivalent to a variac setting of: 1-10 ml 3% ml 10% ml 25% 300 ml - 2 L 50% > 2 L 100% TIP: Because the power switch acts like a variac, if the reaction is heating too slowly or you need more power (e.g., heating to high temperatures), give the heater more power by turning the power level up one setting. If the reaction needs less power than normal (e.g., heating to low temperatures <60 o C) or the temperature overshoots the set point excessively, turn the power down one setting. DO NOT set the power switch on a setting too high initially to heat the reaction quickly and then lower it to the correct setting, this degrades heating performance. 4 Enter the setpoint (i.e., the desired temperature). Hold in the * button and simultaneously press the key to increase or the key to decrease the setpoint. The setpoint can be seen at anytime by holding in the * button, the setpoint appears as a blinking number in the display. 4

5 5 Set the timer. When power is applied to the controller, by default, the timer turns power OFF to the heater as a safety precaution. To turn power On to the heater, briefly push in on the round timer knob and the display changes to ON to show that power to the heater is ON. For complete instructions on the user of the timer see the section titled Timer Controls. If the display does not change when the timer knob is pressed. make sure that the Power Level Switch is not set to the Heat Off position. KEM-Net Data Logging and Control Software The USB port on the back panel of the controller is an interface to J-KEM s KEM-Net Software. KEM-Net is free and can be downloaded from J-KEM s web site at KEM-Net provides remote control of up to 8 controllers, graphical presentations of each digital meter and time & temperature plots. Highlights of KEM-Net include: * GLP and GMP compliant data logging * Runs a 12 step temperature ramp * Logging of Time and Temperature * Logging of % Power for Exo and Endotherm detection * Program KEM-IO Actions (Section 3.11) * Over- & Under-temperature alarm functions. KEM-Net also includes a virtual comm port driver that provides a simple ASCII interface to operate and data log the controller from LabView or other software packages. New Features: GMP compliant data logging Exo and Enotherm monitoring KEM-IO Remote Control of Laboratory Equipment based on Time and Temperature KEM-IO is an optional feature that allows the controller to respond to inputs from instruments, like a vacuum sensor or a hood door switch, and also to control instruments, like stirrers and chillers based on reaction temperature. KEM-IO automates programs as simple as: Heat my reaction to 80 o C, then turn on my peristaltic pump to add reagents. or as sophisticated as: Turn on my stirrer, then ramp my reaction from 25 o C to 100 o C if 45 minutes, hold for 2 hours, then turn off heating. When the reaction cools to 50 o C, turn off the stirrer. If at any point the reaction exotherms and heats above 110 o C, turn on my chiller and keep it on until I manually reset the system. Contact J-KEM for additional information. 5

6 Section 2: Adjusting The Controller For Stable Control With Different Heaters [NOTE: The discussion is Section 2 only applies to the Setpoint Controller meter. The Limit Controller is never tuned and has no affect on the Setpoint Controller meter] 2.1 What is Tuning. The controller's most powerful feature is its ability to regulate virtually any heater with stable temperature control. For stable control the controller requires two things; (1) the controller must be set to the correct power level (see Section 3.6) and, (2) that it must be tuned to the heater being used. Tuning is the process that matches the control characteristics of the controller to the heating characteristics of the heater. The controller is said to be tuned to the heater when its memory is programmed with values telling it how fast the heater warms up, cools off, and how efficiently it transfers heat. For example, consider the difference between a heat lamp and a hot plate. When electricity is applied to a heat lamp it begins to heat instantaneously, and when it's turned off it stops heating instantaneously. In contrast, a hot plate may take several minutes to begin heating when electricity is applied and even longer to start cooling when electricity is turned off. Your controller can regulate both a heat lamp and a hot plate to 0.1 o C. But, to do this it must be programmed with the time constants describing how fast the heater heats when electricity is turned on and how fast it begins to cool when it's turned off. These time constants are called the tuning parameters. Every type of heater has its own unique set of tuning parameters. For the controller to heat with stability, it must have programmed with the tuning parameters for the heater currently being used. Prior to shipment, tuning parameters were programmed into the controller that maximize heating performance for laboratory heating mantles since these are the most common heaters used in research. Tuning is regulated by 5 of the temperature meter s user programmable functions. The correct value for these 5 functions can be calculated and loaded by the user manually, or the controller can do it automatically with its autotune feature When Should the Controller be Tuned? If the controller is tuned to one type of heater, heating mantles for example, any size-heating mantle can be used without the need to retune. When changing from heating mantles to a different type of heater, an oven for example, the controller should be tuned with values describing the oven s heating characteristics. The effects of tuning are seen below. When the controller is tuned for heating mantles, using it with any size-heating mantle yields stable temperature control (Plot 1), but poor control results when the same tuning parameters are used with an oven (Plot 2, Curve 1). However, after tuning the controller to the oven, stable temperature control results (Plot 2, Curve 2). 6

7 It s important to understand that this controller isn t a simple ON/OFF type controller (i.e. ON when below the set point, OFF when above [though it can be made to work this way, see Section 3.13]). Rather it s a predictive controller. Based on the shape (slope) of the heating curve, the controller predicts (calculates) the percent of power to apply to the heater now to control the shape of the heating curve minutes in advance. The importance of the tuning parameters is that they are constants in the equation the temperature meter uses to perform its predictive calculations. If the temperature meter is programmed with tuning parameters that incorrectly describe the heater being used, poor temperature control will result. But, when the correct values are loaded, temperature regulation of ± 0.1 o is typically achieved. Manual Tuning. Manual tuning is when the values of the 5 tuning parameters are determined manually then entered into the temperature meter via the push buttons on the front of the controller. Experienced users might prefer to manually tune the controller since this allows customization of the heating process. Autotune. Autotune is a feature built into the temperature meter that automatically calculates the tuning parameters (i.e. delay times, heating efficiency, etc.) for any type of heater. After the autotune procedure is complete and the tuning parameters are determined, the controller loads them into its memory for current and future use. Heating mantles are a special case and are covered in a separate paragraph (Section 2.3). 2.2 Autotuning Procedure. This procedure is not recommended for heating mantles (see Section 2.3). Only the main Setpoint Controller (the meter on the far left) should be autotune, the Limit Controller can not be tuned. 1. Set the equipment up in the exact configuration it will be used. For example, to tune to a vacuum oven, place the thermocouple in the room temperature oven and plug the oven into the controller. If the oven (or heater) has its own thermostat or power control, turn both as high as they ll go. 2. Set the controller to the appropriate power level (see Section 3.6). Turn the controller and heater on, and enter the desired set point temperature. If the set point isn t at least 30 o C above ambient, skip this procedure and go to the next procedure, Autotuning the Controller for Very Fine Control 3. Enter a temperature in the Limit Controller about 25 o C higher than the set point entered into the Setpoint Controller meter. 4. Press and hold in both the and buttons (for 3 seconds) on the front of the temperature meter until the word tune appears in the display then release both buttons. 5. Press the button (5 times) until CyC.t appears in the display (if you go past this setting, press the button until you get back to it). 6. First, hold in the * button, while holding in the * button press the button. Continue to hold both buttons in until the display reads A --, or A ## where ## is some number. 7. Release the * button and press the button until tune once again appears in the display. 8. Press and hold the * button and tune will change to off to indicate that autotune is currently off. 9. While holding in the * button, press the button to change the display to on, then release both buttons. 10. Press and hold both the and buttons (for 3 seconds) until the temperature appears in the display. The controller is now in its autotune mode. While in autotune the display alternates between tune (for autotune) and the process temperature. When the autotune sequence is done (this may take in excess of an hour) the controller stops displaying tune and only displays the process temperature. [To abort autotune manually, repeat steps 4, 9 and 10 except in step 9 press the button until off is displayed]. 7

8 The autotune sequence. During autotune the controller heats to 75% of the set point temperature, where it oscillates for several cycles before loading the new tuning parameters. After the tuning parameters are loaded it heats to the set point temperature. Tuning below the set point prevents any damage that might occur from overheating. Autotuning the Controller for Very Fine Control. This procedure is not recommended for heating mantles (see Section 2.3). In the majority of cases, the procedure above results in stable temperature control with any heater. A second version of the autotune routine is available and can be used when the heater is already at or close to the set point, is being tuned at a temperature close to room temperature, or for very fine control in demanding situations. If stable temperature control doesn t result after performing the first autotune routine, the procedure below should be performed. Before performing the fine tune autotune procedure, the regular autotune procedure that precedes this should normally be performed. Only the main Setpoint Controller (the meter on the far left) can be autotuned, the Limit Controller will not be tuned. 1. Set the equipment up in the exact configuration it will be used. If the heater has its own thermostat or power controls, turn both as high as they ll go. With this procedure it s not necessary for the equipment to start at room temperature. This procedure can be performed at any time and any temperature. 2. Set the controller to the appropriate power level (see Section 3.6). Turn the controller and heater on, and then enter the desired set point temperature. 3. Enter a temperature in the Limit Controller meter about 25 o C higher than the set point entered into the Setpoint Controller meter. 4. Press and hold in both the and buttons (for 3 seconds) on the front of the temperature meter until the word tune appears in the display then release both buttons. 5. Press the button (5 times) until CyC.t appears in the display (if you go past this setting, press the button until you get back to it). 6. First hold in the * button, while holding in the * button press the button. Continue to hold both buttons in until the display reads A --, or A ## where ## is some number. 7. Release the * button and press the button until tune once again appears in the display. 8. Press and hold the * button and tune will change to off to indicate that autotune is currently off. 9. While holding in the * button, press the button to change the display to At.SP, and release both buttons. 10. Press and hold both the and buttons ( 3 seconds) until the temperature appears in the display. The controller is now in its autotune mode. While in autotune the display alternates between tune (for autotune) and the process temperature. When the autotune sequence is done (this may take in excess of an hour) the controller stops displaying tune and only displays the process temperature. [To abort autotune manually, repeat steps 4, 9 and 10 except in step 9, press the button until off is displayed]. 8

9 Autotune Errors. The autotune routine can fail for several reasons. If it fails, the controller displays the error message tune FAiL. To remove this message, turn the controller off for 10 seconds. Try the procedure titled Autotuning the Controller for Very Fine Control above. If autotune fails again, call and discuss your application with one of our engineers. A common problem when tuning at high temperatures or with large volumes is for the heater to be under powered. A more powerful heater may be needed (contact J-KEM for assistance). 2.3 Tuning for Heating Mantles: A Special Case. This section gives special consideration to heating mantles, since they re the most commonly used heaters in research. Every heating mantle size has its own optimum set of tuning parameters and if you wanted, the controller could be tuned (or autotuned) every time a different size was used. However, this is cumbersome and is also unnecessary. Factory tests show that there s one set of tuning parameters that delivers good performance for all heating mantle sizes. These tuning parameters were loaded into the controller at the factory prior to your receiving it. If you are using a heating mantle and none of the parameters have been changed or the controller hasn t been autotuned since you ve received it, you re ready to go. If the tuning parameters have been changed or the controller has been autotuned and you want to go back to using heating mantles, J-KEM recommends that the tuning parameters for heating mantles be loaded manually (i.e., don t autotune to the heating mantle) by following the step-bystep instructions given in Procedure 1 of Section Sensor Placement. Placement of the sensor is basically common sense. The sensor should be positioned to sense the average temperature of the medium being heated. That means the thermocouple should be shielded from direct exposure to the heater but not so distant that a rise in temperature isn t sensed by the controller within a reasonable period of time. Several examples follow that show the type of consideration that should be given to sensor placement. Solutions Use With: HPLC column heated with a heating tape Oven Place the sensor in the solution. Stir vigorously so that heat is homogeneously mixed throughout the solution. Tape a thin wire thermocouple directly to the HPLC column. Place several layers of paper over the thermocouple to insulate it from the heating tape (the thermocouple should sense the column temperature, not the heater temperature). Wrap the HPLC column completely with heating tape. The thermocouple needs to be shielded from transient hot and cold air currents. Don t place the thermocouple near the heating coil or an air vent. A small thermocouple (1/16 or 1/8 thermocouple) that responds rapidly to changes in air temperature is better than a larger one. 9

10 Section 3: Operations Guide 3.1 Front Panel Description. It s important to remember that this controller has two completely independent controllers in a single cabinet. The description of the operating characteristics of one channel are identical to those of the second channel. No setting on Channel 1 affects Channel 2 and visa versa USB port (on back) Figure 1 NOTE: The controls for Channel 1 and Channel 2 are independent of each other. The description of the controls for Channel 2 are identical to the description of those for Channel 1 presented below. 7 J-KEM highly recommends that all users read Section How to Set Up a Reaction with J-KEM Scientific s Digital Temperature Controller prior to using the controller for the first time. 1. Temperature Display. Shows temperature of the process as the default display. Shows set point temperature (i.e. desired temperature) when * button is pressed. 2. Control Key. When pressed, the display shows the set point temperature. To decrease or increase the set point, press the key (3) or key (4), while simultaneously pressing the control key. The set point appears as a blinking number in the display. 3. Lowers set point when * button (2) is simultaneously pressed. 4. Raises set point when * button (2) is simultaneously pressed. 5. Limit Controller sets the temperature that causes the over temperature circuit to activate disconnecting power from outlets 8 (see Section 3.2.A). 6. Indicates an over temperature condition when lit. See Section 3.2.A. 7. Temperature Sensor Input. Use the same type of sensor probe as the sensor plug installed on the controller (see Section 3.4). The correct sensor type has the same color plug as the receptacle (7) on the front of the controller. To operate properly, the receptacle on the left (connected to the Setpoint Controller ) and the one on the right (the Limit Controller ) must each have a thermocouple attached. 8. Power Outlet. Plug only 120 VAC devices into this outlet. See Section Over Temperature Reset Switch. Press button to reset the over temperature circuit. The temperature on the limit controller (5) must be above the present reaction temperature to reset this circuit. 10

11 10. Controller On/Off switch. For maximum accuracy of the displayed temperature, turn on the controller 15 minutes prior to use. 11. Power Reduction Circuit. Limits the maximum power to the heater. See Sections 3.7 and Timer Display. The timer display always shows the status of the timer circuit (see Section 3.6). The display can show On meaning that the circuit will allow power to be applied to the heater, Off, meaning that the circuit will not allow power to be applied to the heater, or it will show a time when power will be applied or removed from the heater depending on the settings in the timer. 13. Timer Function Knob. Multi-function knob that selects timer function (push knob in) and enters the amount of time in the timer (rotate). See Section Timer State LED s Timer status LED s indicate whether power will be applied or removed from the heater when the time in the timer goes to 0. See Section Heater Status LED. This (small) LED is On when power is being applied to the heater and Off when power is not applied to the heater. 16. USB communications port is on the back of the controller. 11

12 3.2 Setting the Controller for Safe Operation. Two completely separate controllers are contained in the J-KEM Model 280 and it s important to understand what each controller does in order to take full advantage of the Model 280 s safety benefits. Setpoint Controller The meter that controls reaction temperatures. The meter on the left, labeled Setpoint Controller is the main temperature controller and is responsible for all aspects of temperature control including heating, cooling, maintaining the temperature, tuning, etc. The desired solution or process temperature is entered into this controller. This is the meter that the desired reaction temperature is entered into. This meter is equipped with ramp-to-setpoint and soak feature (see Section 3.3). Limit Controller The over-temperature meter. The meter on the right labeled Limit Controller is the over-temperature meter. The only purpose of the Limit Controller is to turn power off if the reaction temperature reaches the temperature limit entered into this meter. The Limit Controller acts as a backup controller, or watchdog, for the Setpoint Controller, the meter that regulates reaction temperature. Setting up an experiment with the Model 280 is quite simple. Place the dual element thermocouple in the process to be heated and turn the controller on. Enter the desired temperature into the Setpoint Controller (for example 80 o C) then a slightly higher temperature into the Limit Controller (for example 85 o C). Press the reset button (9). The Setpoint Controller will heat the process to 80 o C where it will maintain it indefinitely. The only time the Limit Controller comes into play is if, for whatever reason, the temperature of the process rises to 85 o C at which point power is removed from outlets 8. Also, in the event of a power failure, when power is restored the Limit Controller removes power from these outlets. In either event, power remains disconnected until being manually reset. The operation of the Limit Controller can be verified at any time by entering a temperature lower than ambient which should activate the over temperature protection circuit indicated by light 6 coming on. The Model 280 derives its unique safety advantages from its design in which the temperature sensing ability and action of the two controllers are completely independent of the other. Considering the way the controller responds to different types of failures demonstrates the safety benefits of this construction. If the Limit Controller fails closed, the over temperature protection circuit is activated disconnecting all power to the heater. If it fails open, this has no effect on the temperature regulation of the Setpoint Controller, which continues to maintain the desired temperature of the process. If the Setpoint Controller fails closed (the most dangerous failure mode (i.e. uncontrolled full power to the heater)) the Limit Controller activates the over temperature protection circuit permanently disconnecting all power to the heater. If the Setpoint Controller fails open the process simply cools to room temperature. Since each controller has its own thermocouple a failure with either thermocouple results in the same scenarios as above. The Model 280 provides complete 100% redundant control of the heating process for maximum safety of unattended operations. 12

13 3.3 Ramp-to-Setpoint & Soak Feature. A new feature of J-KEM s controllers called Ramp-To-Setpoint allows you to enter a specific heating rate (e.g., heat to 120 o C at a rate of 5 o C/Hour), a second feature called Soak then lets you specify how long to stay at that temperature before turning off. Examples of Program Ramps The controller is shipped with the Ramp-to-Setpoint feature OFF, the user must specifically turn Ramp-to- Setpoint ON. When Ramp-to-Setpoint is OFF, the controller heats to the entered setpoint at the fastest rate possible. When Ramp-to-Setpoint is ON, the controller heats at the user entered ramp rate. The Ramp-to-Setpoint feature and its associated parameters are turned on and set in the controller s programming mode. The parameters of importance are: SPrr SetPoint Ramp Rate. Allowable Values: 0 to 9990 deg/hr. This specifies the desired rate of heating (cooling). Note, this parameter specifies the desired rate of heating (or cooling). SPrn SetPoint Ramp Run. Allowable Values: ON, OFF, Hold This parameter turns the Ramp-to-Setpoint feature ON or OFF. During an active run, if this parameter is set to Hold, the setpoint ramp stops and holds at its current value. This continues until the parameter is set to ON or OFF. When set to OFF, the values in SetPoint Ramp Rate and Soak Time are ignored. SoAK Soak Time. Allowable Values: - -, 0 to 1440 min. This specifies the amount of time to soak at the setpoint temperature after the ramp is complete. A setting of - - causes the controller to remain at the final setpoint indefinitely. A numeric value causes the controller to stay at the setpoint for the entered time and then turn power to the heater off after the time expires. Important Points to Know 1. While the Ramp-to-Setpoint feature in activated, the display alternates between the current reaction temperature and the word SPr to indicate that a SetPoint Ramp is active. 2. If this controller is equipped with a digital 100-hour timer, the digital timer and the Ramp-to-Setpoint feature are completely independent of each other. For example, if the digital timer is set to turn heating OFF after 5 hours, heating is turned off even if a ramp step is in progress. Likewise, if a Soak time turns heating off after 3 hours and the digital timer is set to turn heating off after 10 hours, the digital timer has no effect since the expired Soak time already has turned heating off. 13

14 3. Once the Ramp-to-Setpoint feature is activated in programming mode, it remains on until it s deactivated in programming mode. The Ramp-to-Setpoint feature remains activated even when power is turned off, and then turned back on. 4. Setting a ramp rate in the digital controller does not guarantee that the reaction itself will ramp at the entered value, since the rate of heating is dependent on the power of the heater. Setting a ramp rate in the controller only guarantees that the controller s setpoint will be changed at the entered rate. For the reaction temperature to increase temperature at the specified rate, the heater must have sufficient power to heat at the entered rate. This is a critically important point, the user must understand that the electronic setpoint in the controller will ramp at the entered rate, but the controller cannot force a heater to heat a reaction faster than it s capable of doing. For example, see the plots below. Plot 1 This plot uses a heating mantle to ramp temperature in reaction from 20 to 80C in 60 minutes. The reaction temperature closely matches the setpoint of the controller because heating mantles have enough power to heat a typical reaction at the modest heating rate of 1 degree per minute. Plot 2 In this example, the ramp rate is set to 600 C/ hour, or 10 C per minute. The controller ramps the setpoint at the requested rate, but the reaction temperature does not match the ramp, because the heater does not have enough power to heat the reaction as such a high rate. Every time the reaction temperature does not match the entered ramp rate, it s because the heater has insufficient power to heat at the requested rate. The only solution to this situation is 1) use a more powerful heater, or 2) lower the ramp rate to a value that does not exceed the heaters maximum heating rate. The controller has no influence over a heater that has insufficient power to heat at the entered ramp rate. Plot 1 Plot 2 Controller Setpoint 80 Reaction Temperature Controller Setpoint Reaction Temperature Hours Hours 14

15 Activating & Programming the Ramp-to-Setpoint Feature 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key (8 times) until the word SPrr appears in the display. This is where you set the ramp rate in units of degrees/hour. First hold in the * key, then while holding in the * key press the or key until the desired ramp rate appears in the display, then let go of all the keys. Units are in degrees/hour. 3. Press the key once and the word SPrn will appear in the display. This function turns the ramping feature ON, OFF, or to Hold. First hold in the * key, then while holding in the * key press the or key until the desired setting appears in the display, then let go of all the keys. 4. Press the key once and the word SoaK will appear in the display. This is where the soak time is set in units of Minutes. A soak time of -- means to soak forever (this setting is one below 0 ). First hold in the * key, then while holding in the * key press the or key until the desired time appears in the display, then let go of all the keys. If a soak time is set, the controller display will alternate between showing the current reaction temperature and the word StoP when the soak time has expired to indicate that power has been turned off. 5. To exit programming mode, press and hold in both the and keys until the temperature appears in the display, then release both keys. Deactivating the Ramp-to-Setpoint Feature 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key (9 times) until the word SPrn appears in the display. This function turns the ramping feature ON and OFF. First hold in the * key, then while holding in the * key press the or key until OFF appears in the display, then let go of all the keys. 3. To exit programming mode, press and hold in both the and keys until the temperature appears in the display, then release both keys. 3.4 Temperature Sensor Input. Each controller is fitted with a specific type of temperature sensor input and can only be used with a temperature sensor of the same type (thermocouple or RTD). For the correct temperature to be displayed, the thermocouple type must match the receptacle type on the front of the controller (Figure 1; #7). All thermocouples are color coded to show their type (Blue = type T; Yellow = type K; Black = type J). The color of the thermocouple plug must match the color of the receptacle on the front of the controller. The thermocouple plug on the left is connected to the Setpoint Controller and that on the right to the Limit Controller. If the thermocouple to either unit becomes broken or disconnected, the controller displays an error message and stops heating. Rather than using one dual element thermocouple, 2 single element thermocouples can be used if desired. 15

16 3.5 Timer Controls. This section applies to the Model 210/Timer only. The timer circuit works in conjunction with the digital meter to determine when power is applied to the heater. The digital meter is the actual temperature controller, the timer circuit only acts as a gatekeeper to determine if the digital meter (temperature controller) is allowed to apply power to the heater or not. By inserting the timer between the digital meter and the heater, the timer can turn heater power On or Off based on a user entered time. When power to the controller is turned on, the timer defaults to the Power Off state as is indicated by the word Off in the display. In this state no power is applied to the heater. This is a safety feature that insures that power is not applied to a heater following recovery from a power failure. The timer has 4 states. The timer cycles between the 4 states by pushing in on the silver timer knob momentarily. For example, push the timer knob once and the timer changes from the Off state to Push Push Push Push NOTE: Pushing in on the timer knob quickly for about 1/4 second causes it to advance to the next state. Holding in the knob for 1 second changes to the mode where time is entered into the timer. the On state, push it again and it changes to the toff state. Repeatedly pushing the knob cause the time to cycle between its three normal states of On, toff, and t-on. If the Power Reduction Circuit (Section 3.6) is set to the Heat Off position, the timer window always displays off. The four states of the timer circuit are explained below. In the off state, no power is applied to the heater, even if the temperature meter calls for power to be applied. The controller always enters the off state when power is turned on or following recovery from a power failure. The controller also enters the off state when the power reduction circuit is set to the Heat Off position (see Section 3.6). In the on state, the timer circuit applies power to the heater when the temperature meter calls for power to be applied. Whenever power is applied to the heater, the small LED dot on the left of the timer window is lit. Depending on the power needs of the heater, this dot may blink rapidly. The toff state (standing for Time Off) allows the user to enter the amount of time the controller should heat until heating is automatically turned off. While time is present in the timer, power is applied to the heater, when the time counts down to 0, heating is turned off. See the section below titled Heating for a Set Period of Time. The t-on state (standing for Time On) allows the user to enter an amount of time to delay before applying power to the heater. While time is present in the timer, no power is applied to the heater even if the temperature meter calls for power to be applied, but when time counts down to 0, heat is turned on indefinitely. See the section below titled Delay Heating for a Set Period of Time. 16

17 Over View of the Timer Functions The timer knob is a multi-function knob. When it s pushed in for 1/4 second it causes the timer to advance to the next function. When it s pushed in for 1 second it enters programming mode. In programming mode, the user enters time into the timer or locks the entered time into the timer which starts the program running (a running program can be aborted by holding in the timer knob for 1 second). When in programming mode, rotating the knob in a clockwise direction increases the amount of time entered into the timer. Rotating the knob in a counter clockwise direction decrease the amount of time (when rotating in a counter clockwise direction, the timer rolls over from 00 to 59 minutes, when entering minutes, or from 00 to 99 hours, when entering hours). When the timer counts to 00:00, power is turned Off indefenently Function Change Push knob for 1/4 second When the timer counts to 00:00, power is turned On indefenently To immediately exit a timed run, hold in the timer knob for 1 second Function Change Push knob for 1/4 second Push knob for 1/4 second Function Change Hold in knob for 1 second Program Change Push knob for 1/4 second Function Change Hold in knob for 1 second Program Change Function Change Push knob for 1/4 second Enter Minutes then Enter Hours Hold in knob for 1 second Push knob for 1/4 second Hold in knob for 1 second Program Change Function Change Program Change Enter Minutes then Enter Hours To immediately exit a timed run, hold in the timer knob for 1 second 17

18 Heating for a Set Period of Time In this mode, the user enters the amount of time to heat before turning heating off permanently. This is useful to heat a reaction or other lab instrument for a set period of time and then have the reaction stop heating automatically. While at this setting and while entering a time into the timer, no power is applied to the heater. Step 1. When the timer displays toff, holding in the timer knob causes the display to change to a clock showing 00 : 00. The left 2 digits are hours and the right 2 digits are minutes. The minutes digits are blinking which indicates that their value can be changed. Hold in the timer knob for 1 second Step 2. To increase the number of minutes, rotate the timer knob to the right. To decrease the number of minutes, rotate the timer knob to the left. Step 3. To change the number of hours in the display, momentarily press the timer knob (1/4 second) and the hours digits begin to blink. To increase the number of hours, rotate the timer knob to the right. To decrease the number of hours, rotate the timer knob to the left. Step 4. When the desired time is displayed, hold in the timer knob for 1 second to enter the time and start the timer. When the timer starts, the LED under the label OFF at Zero lights. This indicates that power to the heater will turn OFF when the timer counts down to zero. At any time, the timer program can be aborted by holding in the timer knob for 1 second. When this is done, the display changes to toff. To turn on heating, push the timer knob twice until the display reads On. Momentarily push knob to lock in minutes Rotate the knob to enter minutes Rotate knob to enter hours Hold in timer knob for 1 second to store time and start timer Push Push 18

19 Delay Heating for a Set Period of Time In this mode, the user enters an amount of time to delay before turning on power to the heater. This is useful to start heating a reaction or piece of equipment automatically at a specific time. While at this setting and while entering a time into the timer, no power is applied to the heater. Step 1. When the timer displays t-on, holding the timer knob in for 1 second causes the display to change to a clock that shows 00 : 00. The left 2 digits are hours and the right 2 digits are minutes. The minutes digits are blinking which indicates that their value can be changed. Step 2. To increase the number of minutes, rotate the timer knob to the right. To decrease the number of minutes, rotate the timer knob to the left. Step 3. To change the number of hours in the display, momentarily press the timer knob (1/4 second) and the hours digits begin to blink. To increase the number of hours, rotate the timer knob to the right. To decrease the number of hours, rotate the timer knob to the left. Step 4. When the desired time is displayed, hold in the timer knob for 1 second to enter the time and start the timer. When the timer starts, the LED under the label ON at Zero lights. This indicates that power to the heater will turn ON when the timer counts down to zero. At any time, the timer program can be aborted by holding in the timer knob for 1 second. When this is done, the display changes to t-on. To turn on heating, push the timer knob until the display reads On. Momentarily push knob to lock in minutes Hold in the timer knob for 1 second Rotate the knob to enter minutes Rotate knob to enter hours Hold in timer knob for 1 second to store time and start timer Hold in knob for 1 second 19

20 3.6 Power Reduction Circuit. This circuit (11) limits the maximum output power delivered by the controller. It determines whether the controller heats at a very low (1-10 ml), low ( ml), intermediate ( ml), medium (300 ml - 2 L), or high (>2 L) power level. The power reduction circuit acts as a solid state variac. The table to the right shows the maximum output power from the controller to the heater depending on the position of the power switch. A new power setting was added to this circuit that is not labeled on the front of the cabinet. The new setting is 1 click to the left of the 1-10 ml setting and is power off. In this position the controller doesn t heat but acts as a digital thermometer. The correct setting for this switch is the setting that supplies adequate power for the heater to heat to the set point in a reasonable period of time while at the same time not overpowering it. See Section 4.4 for a detailed explanation of how to correctly set up a reaction using your J-KEM controller. Front Panel Volume Range [New setting to the left Approx. % of Full Power of the 1-10 ml setting] ml ml ml ml - 2 L 50 2 L 100 Heating Liquids. Each power level is associated with a volume range that acts as a guide when heating solutions with heating mantles. When solutions are heated with heating mantles set the power switch to the range that includes the volume of solution being heated [Note: this switch is set to the volume of solution, not the size of the flask]. For example to heat 250 ml of toluene to 80 o C in a 1L round bottomed flask choose the third power setting ( ml) since the solution volume falls within this range. There are situations when a power level other than that indicated by the front panel should be used: Example Power Setting Explanation 80 ml toluene 100 ml flask 100 ml heating mantle SP = 80 o C 80 ml collidine 100 ml flask 100 ml heating mantle SP = 170 o C 80 ml water 100 ml flask 100 ml heating mantle SP = 80 o C 125 ml toluene 1 L flask 1 L heating mantle SP = 80 o C 150 ml toluene 250 ml flask 250 ml heating mantle SP = 35 o C ml (25% power) 300 ml - 2 L (50% power) 300 ml - 2 L (50% power) ml (10% power) ml (10% power) Organic solvents heated to o C are set to the volume range on the front panel. When choosing between 2 power settings (i.e. 80 ml also falls within both the ml range and the ml range) choose the higher setting. Even though the solvent volume is less than the range of this power setting, it should be used because high temperatures require additional power. While the setting ml would work, since the heat capacity of water is twice that of a typical organic solvent (1 cal/g/ o K), a higher power setting can be used to compensate for the higher heat capacity. When the heating mantle size is substantially larger ( 5X) than the volume being heated (i.e. the heating mantle has excess heating capacity for the volume being heated), a lower power setting gives better control. Even though the solvent volume isn t included in this power setting, it should be used because low temperatures are better regulated with less power. 20

21 Avoid switching between the different power levels while the controller is heating. Specifically, do not initially set the controller on a high power level to rapidly heat the solution, and decrease the power level to the correct setting as the solution approaches the set point. Changing power levels doesn t damage the controller, but it will reduce its heating performance. Heating Equipment. Two factors need to be considered when heating equipment (ovens, hot plates, furnaces, HPLC columns, etc.); (1) placement of the temperature sensor (Section 2.4) and, (2) the appropriate power setting. The best guide to the correct power setting for various pieces of equipment is the researcher's experience. If your best guess is that the equipment needs 1/3 full power to heat to the set point, set the power switch on the 300 ml - 2 L setting (i.e., 50% power, it s usually better to have too much power rather than too little). If the heater heats too slowly, increase the power (to the >2 L setting), if it heats too fast or has excessive overshoot, decrease the power (to the ml setting). If the amount of power seems to be adequate, but the heater doesn t heat with stability, the controller probably needs to be tuned (see Section 2). Section 3.7 shows the type of performance you should expect from the controller with different pieces of equipment. 3.7 Effect of Power Setting on Heating Profile. The following graphs show the effect of selected power levels on heating performance in a variety of situations. Each example contains 1 optimal and 1 or 2 less optimal settings demonstrating use of the power reduction circuit. Temp o C o Conditions: Set point = 75 C Laboratory oven Power Setting = ml Power Setting = > 2L o Conditions: Set point = 45 C HPLC Column wrapped with heating tape Power Setting = ml Time (min) Graph 1 This graph shows typical heating profiles for a laboratory oven and an HPLC column. In the example of the oven the heating curves for 2 different power levels are shown. The ml setting is the appropriate amount of power to heat to 75 o C and thus results in a smooth heating curve. The > 2L power setting is too much power and results in oscillation around the set point. 21

22 Graph 2 This graph shows the affect of different power settings when heating liquids with heating mantles. The ml setting (10% power) is under powered and results in slow heating. The 300 ml - 2 L setting (50% power) is too much power and results in sporadic control. The controller adapts to a wide range of power settings. In this example the power is varied by a factor of 5X, nevertheless, reasonable control is maintained in each case. Graph 3 Another factor affecting the choice of power setting is the set point temperature. For set points near room temperature a low power level is adequate. For average temperatures ( o ) the volumes printed on the front of the controller is a good guide. For high temperatures, the next higher power setting might be needed to supply the heater with additional power. The power reduction circuit limits the total amount of power delivered to the heater. In this sense it works like a variac and can be used like one. If the heater isn t getting enough power, turn the power level up one notch, and if it s getting too much power, turn it down. 22

23 3.8 Do's and Don'ts When Using Your Controller. The controller, heater and thermocouple form a closed loop feedback system (see Fig. 2 in Section 4.1). When the controller is connected to a heater, the feedback loop should not be broken at any point. Don't Don't Do Do Do remove either the thermocouple or heater from the solution without setting the power level to the "Heat Off". With the thermocouple or heater separated from the solution, as the thermocouple cools the controller turns the heater on. Since this heat is never fed back to the controller it heats continuously. use the controller to regulate an exothermic process. The controller has no capacity for cooling. If an exotherm is expected, it must be controlled in another way. use an appropriate size flask and heater for the volume being heated. Use the smallest flask and heating mantle that accommodates the reaction. This ensures that the heating power of the heating mantle closely matches the volume being heated. This also allows the solution to radiate excess heat to minimize temperature overshoots. place the thermocouple directly in the solution. Place at least the first 1/4 of the thermocouple directly into the solution. If a corrosive mixture is heated, use a Teflon-coated thermocouple (or use the external thermocouple method; Section 4.2). avoid exposure of the controller to corrosive gases and liquids. The atmosphere of a research hood is corrosive to all electronics. Place the controller outside the hood away from corrosive gases. 3.9 Changing the Temperature Display Resolution The controller is programmed to display temperature with 0.1 o C resolution. The controller can be changed to 1 o C resolution if by following the procedure below (the display can also be changed to read in o F, call for information). There are two reasons to change the display resolution: 1) To enter a setpoint faster (the display scrolls 10X faster in 1 o mode than in 0.1 o mode). 2) To display temperatures above o. 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key once and LEVL appears in the display. First hold in the * key, then while holding in the * key press the key until 2 appears in the display then let go of all the keys. 3. Press the key repeatedly until the word disp appears in the display. First hold in the * key, then while holding in the * key press the or key until the value 1 [not 0.1 ] appears in the display, then let go of all the keys. 4. Press and hold in both the and keys until the temperature appears in the display, then release both keys. 23

24 3.10 Resetting the Controller for Use With Heating Mantles. If you want to use your controller with heating mantles after it s been tuned for a different style heater, rather than autotuning the controller with the heating mantle, J-KEM recommends that the controller be manually tuned by following the procedure below. Procedure 1. Perform when using heating mantles with round bottom flasks. [This procedure takes about 2 minutes to perform] 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key once and the word band will appear in the display. First hold in the * key, then while holding in the * key press the or key until the value 10 appears in the display, then let go of all the keys. 3. Press the key once and the word int.t will appear in the display. First hold in the * key, then while holding in the * key press the or key until the value 10 appears in the display, then let go of all the keys. 4. Press the key once and the word der.t will appear in the display. First hold in the * key, then while holding in the * key press the or key until the value 50 appears in the display, then let go of all the keys. 5. Press the key once and the word dac will appear in the display. First hold in the * key, then while holding in the * key press the or key until the value 3.0 appears in the display, then let go of all the keys. 6. Press the key once and the word CyC.t will appear in the display. First hold in the * key, then while holding in the * key press the or key until the value 30 appears in the display, then let go of all the keys. 7. Press and hold in both the and keys until the temperature appears in the display, then release both keys Heater Restrictions. The controller delivers 15 amps of current at 120 VAC into resistive loads (heating mantles, hot plates, ovens, etc.). Use only resistive loads that are safely operated at 120 VAC and require less than 15 amps or damage to the controller and a safety hazard may result. Do not plug oil baths into your controller. Oil baths are not 120 VAC devices and become a fire hazard unless properly connected to the controller. (See Appendix for an application note describing the use of oil baths with this controller) Devices other than resistive loads can be used with your controller but certain restrictions apply. Device Type Restrictions Comments Incandescent lamps Infrared heaters Inductive loads: * solenoids * transformers * motors 1200 watts 6 amps; 720 watts 1/3 horsepower Set the power reduction circuit to the > 2 L position. The controller must be programmed for this use. Request application note AN Fusing. The controller is protected by two fuses. The first protects outlets 8 and is a fast acting fuse designed specifically to protect solid state relays. This is the larger fuse on the back panel of the controller. If this fuse is replaced IT MUST BE REPLACED BY AN EXACT EQUIVALENT, a Tron KAA-15 or Bussman KAX-15. One of these fuses, or an exact equivalent, must be used or a significant safety hazard will be created and will void the warranty. The second fuse protects the Setpoint Controller and is the smaller fuse on the back panel of the controller. This can be replaced with any fast acting 3 amp fuse. 24

25 3.13 Changing Between PID and ON/OFF Operating Modes. The controller can heat in either of 2 operating modes, PID (Proportional, Integral, Derivative) or ON/OFF mode. The difference between them is the way they supply power to the heater. In ON/OFF mode (the simplest heating mode), the controller is ON when it s below the set point and OFF when above. The disadvantage of this mode is a large over shoot of the set point (5-30 o ) on initial warm up and oscillation of temperature around the set point thereafter. The reason for the overshoot is because the heater turns off only after crossing the set point and until the heater cools down the temperature continues to rise. This method works well for heaters that transfer heat rapidly (such as heat lamps), it s acceptable for heaters such as heating mantles ( 5 o overshoot), but it s terrible for heaters that transfer heat slowly (vacuum ovens, heating blocks, etc.). In PID mode the controller monitors the shape of the heating curve during initial warm up and decreases power to the heater before the set point is reached so that the solution reaches the set point with minimal over shoot. [Notice that the heater turns off for varying periods of time before the set point temperature is reached]. The second feature of PID mode is that it adjusts the percent of time the heater is on so that the set point is maintained precisely. The advantage of PID mode is that it delivers stable temperature control with any heater from heat lamps to vacuum ovens. The disadvantage is that the controller must be properly tuned to the heater being used, whereas ON/OFF mode requires no tuning. Since both heating modes have their advantages (simplicity vs. accuracy), instructions to change the controller to ON/OFF mode are given below (though PID mode will probably give better results 95% of the time). The controller can be set back to PID mode by following the procedure in Section Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then let go of the buttons. 2. Press until the word CyC.t appears in the display. 3. While holding in the * key, press the key until the word on.of appears in the display. NOTE: if the display shows the letter A when the * keys is held in, press the key until on.of is in the display, then let go of all the keys. 4. Press the key until the word band appears in the display. While holding in the * key, press the key until the value 0.1 appears in the display, then let go of all the keys. 5. Press and hold in both the and keys on the front of the controller until the temperature is displayed, then release both keys. Procedure to change controller to ON/OFF mode The controller can be set back to PID control by following the procedure in Section To completely reset the controller to original factory settings, follow the procedure in the Appendix, Section II. 25

26 3.14 Troubleshooting. Problem Cause CorrectiveAction Large over shoot of the set point Output power level is set too high. Set the output power level to a lower setting (see Section 3.6). (> 3 o ) during initial warm-up or unstable temperature control. Controller is not tuned for process Tune the controller as outlined in Section 2. being heated. The process heats too slowly. Output power level is set too low. Increase the output power level to the next higher setting (Section 3.6). The heater doesn t have enough power. Replace with a more powerful heater. For assistance contact J- KEM. The controller comes on, but does not heat. The heater is broken. To verify that the controller is functioning properly, place the power level switch on the >2L setting and enter a set point of 100 o C. Plug a light into the outlet of the controller, and wait 1 minute. If the light comes on the controller is working properly. The 15 amp fuse has blown Replace blown fuse. See Section Controller blinks: inpt FAiL PArk The over temperature protection circuit is engaged. The switch on the bottom of the Input/Output board must on the inactive position. The temperature sensor is unplugged, excessively corroded or broken. Controller has been placed in Park mode. Set the Limit Controller to a temperature higher than that shown on the Setpoint Controller, and press the reset button (see Section 3.2). Move switch back to the inactive position. If accessories are attached, see User s Manual for the accessory. Clean or replace broken sensor. 1. Hold in both the and keys on the front of the J-KEM temperature meter until tune appears in the display. 2. First hold in the * key, then while holding in the * key press the key until off appears. 3. Hold in the and keys until the temperature appears in the display. tune FAiL Autotune routine failed. Turn off controller for 10 seconds. See Section 2.2. Displayed temperature is incorrect. [Note: Types K & J ] Thermocouples display negative temperatures, but are not calibrated for them] The controller has not warmed-up. Wrong type of thermocouple is plugged into controller. Corroded thermocouple connections. Corroded thermocouple. Temperature display offset needed. The display temperature reads low when the controller is first turned on, but will self-correct as it warms up. The controller can be used immediately since it will warm up during the initial stages of heating. Thermocouples are color coded. Thermocouple plug and thermocouple receptacle must be the same color (see Section 3.2). Clean plug on thermocouple and receptacle on controller with sandpaper or steel wool. If the temperature-measuring end of the thermocouple is corroded, discard thermocouple. To enter a controller display offset: 1. Turn on controller. Allow unit to warm up for 30 minutes. 2. Record displayed temperature. 3. Press both the and keys on the front of the temperature meter until tune appears, then let go of the keys. 4. Press the key until LEVL appears. 5. First hold in the * key, then while holding in the * key press the key until 3 is showing in the display, then let go of all keys. 6. Press the key until ZEro is showing in the display. 7. Note the current display offset (this is the number blinking in the display). 8. Calculate the new offset temperature using the equation: New Current Display = display offset - Displayed + Correct Offset blinking in display temperature temperature 9. First hold in the * key, then while holding in the * key press the or keys until the new offset temperature is showing, then let go of all the keys. 10. Press the and keys until the temperature is displayed. 26

27 Section 4: Application Notes Supplemental application notes on the following topics are available by contacting J-KEM. Application Note AN1 AN2 AN3 AN4 AN5 Subject How to heat oil baths with your controller. (Included in Appendix) Changing the controller s thermocouple type. Changing the heating outlet into a cooling outlet. Using the controller for unattended fractional distillations. Using the controller with inductive (motors, valves) loads. 4.1 Theory of How the Controller Works Simply. For the purpose of explaining how the controller works, the example of a solution heated with a heating mantle is used. The principles are the same for all heater types. Figure 2 The controller, the heating mantle and the thermocouple form a closed loop feedback system. If the process temperature is below the set point, the controller turns the heating mantle on and then monitors the temperature rise of the solution. If a small rise results (indicating a large volume is being heated) the controller sets internal parameters appropriate for heating large volumes. If a large rise in temperature results, the controller responds by loading a set of parameters appropriate for heating small volumes. For the controller to work ideally, information needs to travel instantaneously around the feedback loop. That means that any power the controller applies to the heating mantle must reflect itself in an instantaneous temperature rise of the solution and the thermocouple. Unfortunately, this type of instantaneous heat transfer from the heating mantle to the solution to the thermocouple just doesn't occur. The delay time between when power is applied to the heating mantle and when the solution rises in temperature; and also the converse, when power is removed from the heating mantle and the solution temperature stops rising is the source of most controller errors. The reason for this can be seen in a simple example. Imagine heating a gallon of water to 80 o C in a 5-quart pan on an electric range. Placing the pan on the range and turning the heat to high you d observe a delay in heating while the range coil warmed-up. This delay might be a little annoying, but it's really no problem. The real problem comes as the water temperature approaches 80 o C. If you turned the range off just as the water reached 80 o C the temperature would continue to rise even though all power had been disconnected until the range coil cooled down. 27

28 This problem of overshooting the set point during initial warm-up is the major difficulty with process controllers. Overshooting the set point is minimized in two ways by your J-KEM controller but first let's finish the range analogy. If you had turned the range off just as the water temperature reached 80 o C, the final temperature probably would not exceed 82 o C by the time the range coil cooled down, because the volume of water is so large. In most situations a 2 o C overshoot is acceptable. But what if you were heating 3 tablespoons (45 ml) of water and turned the stove off just as the temperature reached 80 o C. In this case, the final temperature would probably approach 100 o C before the range cooled down. A 20 o C overshoot is no longer acceptable. Unfortunately, this is the situation in most research heating applications. That is, small volumes (< 2 L) heated by very high efficiency heating mantles that contain large amounts of heat even after the power is turned off. Your controller handles the problem of latent heat in the heating mantle in two ways: 1) The controller measures the rate of temperature rise during the initial stages of heating. It then uses this information to determine the temperature at which heating should be stopped to avoid exceeding the set point. Using the range analogy, this might mean turning the power off when the water temperature reached 60 o C and allowing the latent heat of the burner to raise the water temperature from 60 to 80 o C. This calculation is done by the controller and is independent of the operator. The next feature of the controller is directly under operator control and has a major impact on the amount of overshoot on initial warm-up. 2) Again referring to the range analogy, you'd obtain better control when heating small volumes if the range had more than two power settings; Off and High. J-KEM s patented power reduction circuit (11) serves just this function. It allows the researcher to reduce the power of the controller depending on the amount of heat needed. This circuit can be thought of as determining whether the heating power is Very low (1-10 ml), Low ( ml), Intermediate ( ml), Medium (300 ml-2 L), or High (> 2 L). The proper power setting becomes instinctive after you've used your controller for a while. For additional information see Section Controlling the Heating Mantle Temperature Directly. In a normal heating setup, the thermocouple is placed in the solution being heated. The controller then regulates the temperature of the solution directly. The thermocouple could alternately be placed between the heating mantle and the flask so that the controller regulates the temperature of the heating mantle directly, which indirectly regulates the temperature of the solution. Advantages to this method include: 1. The temperature of any volume (microliters to liters) can be controlled. 2. Temperature control is independent of the properties of the material being heated (e.g., viscosity, solid, liquid, etc.). 3. Air and water sensitive reactions can be more effectively sealed from the atmosphere. The temperature controller must be programmed for use with an external thermocouple before this procedure is used (see following procedure). The following step-by-step procedure programs the controller to regulate heating mantle temperature. If you switch back and use the controller with the thermocouple in solution, Procedure 1 in Section 3.10 will program the controller for heating mantles. For all other heaters, see tuning instructions in Section 2. 28

29 After the controller is reprogrammed, place a fine gage wire thermocouple ( 1/3 the size of kite string; available from J-KEM) in the bottom third of the heating mantle and fit the flask snugly on top so that the thermocouple is in intimate contact with the heating mantle. Set the power reduction circuit to the power level shown in the table at the right. Turn the controller on and enter the set point. Heating Power Mantle Size Level 5 & 10 ml 1-10 ml 25 ml ml 50 ml - 22 L ml For temperatures over 120 o C, the next higher power level may be necessary Procedure to Load Tuning Parameters for External Thermocouples. 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key once and the word band will appear in the display. While holding in the * key press the or key until the value 5 appears in the display, then release all keys. 3. Press the key once and the word int.t will appear in the display. While holding in the * key press the or key until the value 2 appears in the display, then release all keys. 4. Press the key once and the word der.t will appear in the display. While holding in the * key press the or key until the value 5 appears in the display, then release all keys. 5. Press the key once and the word dac will appear in the display. While holding in the * key press the or key until the value 5.0 appears in the display, then release all keys. 6. Press the key once and the word CyC.t will appear in the display. While holding in the * key press the or key until the value 5.0 appears in the display, then release all keys. 7. Press and hold in both the and keys until the temperature appears in the display, then release both keys. To return to using thermocouples in solution, perform Procedure 1 in Section Automatic Storage of Min/Max Temperatures The controller will automatically record the minimum and maximum temperatures of a process by following the procedure below. These temperatures are updated continuously after the routine is started and cleared by turning the controller off. This procedure must be started every time you want to record temperatures. Procedure to Start Temperature Logging 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key once and the word LEUL appears in the display. While holding in the * key press the key until the value 3 appears in the display, then release all keys. 3. Press the key until the word ChEy appears in the display. While holding in the * key press the key until on appears in the display, then release all keys. 4. Hold in both the and keys until the temperature appears in the display, and release both keys. Automatic temperature logging is now on and will remain on until the controller is turned off or logging is turned off manually by repeating this procedure except in Step 3 pressing the key until the word off appears. Procedure to Read Minimum and Maximum Temperatures 1. Press and hold in both the and keys on the front of the temperature meter until the word tune appears in the display, then release both keys. 2. Press the key once and the word LEUL appears in the display. While holding in the * key press the key until the value 3 appears in the display, then release all keys. 3. Press the key until the word read appears in the display. The read screen displays 3 parameters. 1. Variance (the difference between the highest and lowest logged temperatures). Hold in the * key and the display will alternate between UAr o and number of degrees of variance. 2. High Temperature (the highest temperature since the logging option was turned on). While holding in the * key press the key once and the display will alternate between hi o and the highest recorded temperature. 3. Low Temperature. While holding in the * key press the key once and the display will alternate between Lo o and the lowest recorded temperature. The High and Lo temperatures can be examined as often as you like since updating and monitoring continues until, the monitoring is stopped by turning the controller off. 4. Press and hold in both the and keys until the temperature appears in the display, then release both keys. 29

30 4.4. How to Set Up a Reaction with J-KEM Scientific s Digital Temperature Controller This application note shows how to set up a typical heated reaction using J-KEM Scientific s digital temperature controller. For this example, the Model Gemini controller is used, but the application note applies equally well to all J-KEM temperature controller models. If you have questions about specific models of temperature controllers, or any safety related question, please feel free to contact J-KEM Scientific. This application note does not supercede any information in the Controllers actual User manual. The User manual for each model is always the reference for that model. The Model Gemini is a dual channel controller that allows two independent reactions to be run on the same controller, one reaction on Channel 1 and the second on Channel 2. In this example, we will only use channel 1. Gemini Dual Channel Temperature Controller Thermocouple receptacle Channel 1 has a 100 hour to turn heating On (Off) at a user set time. Channel 2 does not have a timer Thermocouple extension cord Thermocouple 30

31 Thermocouples Thermocouples are color coded. When the plastic connector on the end of the thermocouple is blue, it is a type T thermocouple, when it is yellow it is a type K, and when it is black it is a type J. The color of the thermocouple, the thermocouple extension cord, and the thermocouple receptacle on the face of the controller must all be the same color (i.e., thermocouple type) or the controller will not read the correct temperature. Thermocouples are available in many different styles. As long as the thermocouple has the same color connector as the connector on the controller, they are 100% compatible. Stainless steel, no Teflon coating 12 inch length, Teflon coated Bend Teflon coated hypodermic needle 6 inch length, Teflon coated Temperature sensitive end of the thermocouple When a thermocouple is placed in solution, often it is desirable to bend the thermocouple slightly so that more of the tip extends into the solution. It does not hurt a thermocouple to be bent slightly. The temperature sensitive portion of a thermocouple is the first ¼ of the tip. It s good for the first ½ to be is solution, but the first ¼ must be in solution to read the temperature correctly. Heaters Your J-KEM controller works with virtually any 120 volt (or 230 volt heaters outside of the USA) heater, including any size heating mantle, 120 vac oil baths, hot plates, ovens, and many other style heaters. If you have questions about the compatibility of specific heaters, please contact j-kem. 1 liter heating mantle 10 ml heating mantle Oil bath 31

32 Classes of J-KEM Scientific Temperature Controllers J-KEM s 200-Series, Apollo, and Gemini controllers are compatible with any size heating mantle from 5 ml to 50 liter, and any 120 Vac oil bath (do not use with oil baths rated less than 120 Vac). J-KEM s 150-Series economy controllers are compatible with 500 ml heating mantles and larger, and 120 Vac oil baths (do not use with oil baths rated less than 120 Vac). J-KEM s 230 Vac controllers are compatible with any 230 Vac heating mantle 100ml and larger. They are not compatible with any size oil bath. Shown is a typical set up for a solution phase reaction. 1. Place the reaction flask in the appropriate size heating mantle., then plug the power cord from the mantle directly into the power outlet of the temperature controller. 2. Place a stirring bar inside of the flask, in the solution. Place the flask on a magnetic stirrer and stir the reaction for good heat transfer. 3. Place a thermocouple in solution and make sure that at least the first ¼ (1/2 is better) is covered by the fluid in the reaction flask. Thermocouple in solution 100 ml Heating mantle Heater power cord 32

33 4. Enter the temperature that you want to heat the reaction to (i.e., the Setpoint) into the digital meter. To enter the setpoint temperature (i.e., the temperature to heat to) into the controller: 1. Hold in the Star button on the face of the digital meter. 2. While holding in the Star button, press the Up arrow to increase, and the Down arrow to decrease the setpoint temperature. Star button Up (to increase) and Down (to decrease) arrows When the desired setpoint temperature is showing in the display, release the star button to load the setpoint. When no buttons are pressed on the controller, the controller shows the temperature sensed by the thermocouple. When the Star button is pressed, the setpoint appears as a blinking number. 5. Set the correct Power Control Level. Your J-KEM controller has a built in Power Control Computer PCC) that precisely regulates power to the heater. For the computer to work correctly, it must know the volume of solution that is being heated. It s important to understand that the PCC is set to the Volume of solution being heated, not the size of the heater or the size of the flask. 15 ml of solution in a 100 ml flask 75 ml of solution in a 100 ml flask If the flask above is placed in a 100 ml heating mantle, the power control input should be set to the ml setting. The power control computer is always set to the Volume of solution being heated, not the size of the flask or heater. If the flask above is placed in a 100 ml heating mantle, the power control input should be set to the ml setting. When the power control computer is set to the correct power level, your controller can regulate virtually any heater to o C with less than 1 o C overshoot on initial warming. For a detailed explanation of the Power Control Computer, see Section Two in the controller s User manual. 33